Diabetes mellitus

An accidental discovery led to the Nobel Prize for Canadian researchers

The causes of diabetes (pronounced di' e-be' tis), a disease known for
centuries, were explored by German doctors over a century ago, and
further established by two Canadian scientists, who, in 1922, worked
in a laboratory at the University of Toronto. The German researchers
were interested in studying digestion, and used domestic dogs in
experiments. The doctors performed surgery on the animals and
removed a small gland located in the abdomen, just below the stomach.
The gland was called the "pancreas" (named from the Greek words "pan,"
meaning "all," and "kreas", meaning "flesh"), and helps to digest food.
The gland, when taken from beef, is considered a delicacy on the dinner
table because of its nutritious qualities and given the more familiar
sounding name, "sweetbread." It is rich in proteins and enzymes, and
like the liver, is an extremely healthy food.

The research doctors, whose original purpose was to study digestion,
accidentally discovered something else. In the old days of medical
research, animals were usually kept within the laboratory, fed and
cared for by laboratory assistants. Facilities were not as well equipped
as they are today, and animals were housed in the same rooms where
scientists carried out experiments.

In the original laboratory, animals deposited their liquid wastes
(urine) in the corner of the room. In summer, the windows were typically
open, and on occasion, insects, such as ants, would get into the laboratory.
The remarkable thing was that ants, in large numbers, tended to be
attracted to the dog urine. A laboratory assistant first noticed that many
ants were clustered around the urine, which stimulated his curiosity
and eventually led the researchers to their famous discovery. The doctors
tested the urine and were surprised that samples were extremely high in
sugar, indicating high blood sugar levels. It was, therefore, logically
reasoned that the pancreas, which had been removed, had something to do
with the control of blood sugar levels.

In Canada, Drs. F.G. Banting and C.H. Best demonstrated that a
special chemical (called a "hormone", from the Greek word "horme" for
"impulse") keeps the level of sugar at the proper level. This
area of medical research is called "endocrinology", and involves
circulating hormones and the glands from which hormones are made.
Banting, in 1923, was the first Canadian to receive a Nobel Prize
for medicine, and a replica of the Banting-Best laboratory has been
restored for visitors at the Ontario Science World in Toronto.

When the pancreas is removed, the source of the chemical is also
removed, and sugar levels rise above normal. High sugar levels are
unhealthy and can be dangerous. If someone has a defective pancreas,
however, a treatment exists. Patients can give themselves daily
injections of the replacement hormone (called "insulin", from the
Latin word "insula" meaning "island", describing the appearance
of the cells in the pancreas) and, thus, control their blood sugar
levels. Sugar, after all, is a vital chemical that is necessary for
all living things to carry out their activities.

The interesting point about this discovery, of a disease affecting
millions of North Americans, is that the full name of the disease is
"diabetes mellitus". "Diabetes" comes from the Greek word for "siphon",
and implies that a lot of urine is made. The second term, "mellitus"
comes from the Latin word, "mel" which means "honey", and was used
because the urine was sweet. The ants, however, were the real discoverers,
indicating to the laboratory workers that the urine had special properties
worth investigating.